• 전력전자학회논문지
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• 제6권4호
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• pp.325-332
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• 2001

전징기관은 내이에 존재하며 유연한 동작과 몸의 자세 그리고 운동을 조절한다. 이 기관은 회진 가속도를 감지하는 세반고리관과 선형 가속을 감지하는 이석기관으로 구성된다. 이러한 기관의 생체 신호로부터 의사는 사람이 환자인지를 판단한다. 이 신호의 데이터를 얻기 위해서 회전의자 한쪽을 들어올려 최대 30도까지 기울인 상태에서, 회전제어하게 되는데, 이 경우 부하의 불균형으로 인한 불평형 부하를 제거하고, 생체신호의 측정을 위하여 robust제어가 요구된다. 본 연구에서는 자세조절기능에 대한 이석기관의 역할을 추구하기 위하여 탈수직축 회전자극기를 개발하였으며, 공간을 차지하고 다양한 시각패턴을 만들지 못하는 기존 시각자극시스템의 단점을 해결하기 위하여 HMD를 이용한 시각자극 시스템을 개발하였다. 더구나 노이즈에 취약한 아날로그 신호인 ENG신호의 전송문제를 해결하기 위하여 근거리 R/F 무선시스템으로 개발하였다. 이상의 제안된 시스템을 제작하고 실험한 결과를 보고하였다.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2000년도 추계학술대회 논문집
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• pp.62-68
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• 2000

The aim of the study was to compare effects of music and white noise on the recovery of facial blood flow parameters after stressful visual stimulation. Twenty-nine subjects participated in the experiment. Three visual stimulation sessions with aversive slides (the IAPS, disgust category) were followed by subjectively "pleasant" (in the first session), "sad" music (in the second ), and white noise (in the third ). Order of sessions was counterbalanced. Blood flow parameters (peak blood flow, blood flow velocity, blood volume) were recorded by Laser Doppler single-crystal system (LASERFLO BPM 403A) interfaced through BIOPAC 100WS with AcqKnowledge software (v.3.5) and analyzed in off-line mode. Aversive visual stimulation itself decreased blood flow and velocity in all 3 sessions. Both "pleasant" and "sad" music led to the restoration of baseline levels in all blood flow parameters, while noise did not enhance recovery process. Music on post-stress recovery had significant change in peak blood flow and blood flow velocity, but not in blood volume measures. Pleasant music had bigger effects on post-stress recovery in peak blood flow and flow velocity than white noise. It reveals that music exerted positive modulatory effects on facial vascular activity measures during recovery from negative emotional state elicited by stressful slides. Results partially support the undoing hypothesis of Levenson (1994), which states that positive emotions may facilitate process of recovery from negative emotions.

• 융합신호처리학회논문지
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• 제17권2호
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• pp.77-82
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• 2016

운전자에게 각성뇌파를 생성할 수 있는 SSVEP기반의 졸음퇴치 도로시설물 시제품 개발을 위하여 실험을 통한 표준 인터페이스 모델의 개발 및 실험 검증 자료를 구축하는데 있다. 먼저 프로그램 시뮬레이션으로 SSVEP 자극 프로그램을 만들어서 체커 보드의 자극패턴을 만들었고 SSVEP의 주파수를 베타파 영역(13~30Hz) 내에 설정하였다. 고속도로 졸음취약지점에서 설치하여 운전중에 SSVEP 광자극에 대한 효과검증에 관한 실험 결과 주간과 야간 모두 고속도로 운전 중 SSVEP 광자극을 받으면 순간 베타파가 증가하는 것을 확인하였고, 5분 유지기 동안 보다 높은 각성상태를 유지하는 것으로 확인되었다.

• 한국의학물리학회지:의학물리
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• 제30권1호
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• pp.22-31
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• 2019

Purpose: To develop a new diffusion-based functional MRI (fMRI) sequence to generate apparent diffusion coefficient (ADC) maps in single excitation and evaluate the contribution of b0 signal on neuronal changes. Materials and Methods: A diffusion-based fMRI sequence was designed with single measurement that can acquire images of three directions at a time, obtaining $b=0s/mm^2$ during the first baseline condition (b0_b), followed by 107 diffusion-weighted imaging (DWI) with $b=600s/mm^2$ during the baseline and visual stimulation conditions, and another $b=0s/mm^2$ during the last activation condition (b0_a). ADC was mapped in three different ways: 1) using b0_b (ADC_b) for all time points, 2) using b0_a (ADC_a) for all time points, and 3) using b0_b and b0_a (ADC_ba) for baseline and stimulation scans, respectively. The fMRI studies were conducted on the brains of 16 young healthy volunteers using visual stimulations in a 3T MRI system. In addition, the blood oxygen level dependent (BOLD) fMRI was also acquired to compare it with diffusion-based fMRI. A sample t-test was used to investigate the voxel-wise average between the subjects. Results: The BOLD data consisted of only activated voxels. However, ADC_ba data was observed in both deactivated and activated voxels. There were no statistically significant activated or deactivated voxels for DWI, ADC_b, and ADC_a. Conclusions: With the new sequence, neuronal activations can be mapped with visual stimulation as compared to the baseline condition in several areas in the brain. We showed that ADC should be mapped using both DWI and b0 images acquired with the same conditions.

• 감성과학
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• 제26권3호
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• pp.3-14
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• 2023

본 연구는 참가자 간 표상 유사성 분석(intersubject representation similarity analysis: IS-RSA)을 이용하여 3개의 선행연구에서 얻어진 데이터의 참가자 반응 일치성 패턴을 확인하고 각 실험의 정서 조건 간 차이가 있는지 살펴보았다. 3개의 실험은 각각 ASMR 자극, 시각 및 청각 자극, 시계열적 정서 동영상 자극을 사용하였으며 각 실험의 조건에 맞게 정서 평정치와 생리측정치를 측정하였다. 참가자 간 표상 유사성 분석을 계산하기 위해서 각 실험에 있는 각 자극에 대한 참가자들의 측정치를 쌍별로 피어슨 상관계수를 구하였다. 실험의 조건 간 비교를 위해 분산분석과 평균을 비교하였다. 연구 결과, ASMR과 시각 및 청각 데이터의 참가자 간 반응의 일치성은 시계열적 정서동영상 참가자들 반응의 일치성에 비해 일관적이었다. ASMR 실험은 긍정 자극에서 참가자 간 반응의 일치성이 높았다. 청각 및 시각 실험은 높은 각성수준과 시각 자극에서 참가자들의 반응 일치성이 높았다. 본 연구 결과는 생리적, 행동적 반응에 대한 측정치의 IS-RSA가 다차원적인 데이터의 정보를 요약하여 제시하며 이를 하나의 분석 데이터로 변환 가능하다는 것을 확인하였다. 이를 통해, IS-RSA가 참가자들의 반응 일관성에 대한 전반적인 정보를 제시할 수 있는 새로운 분석 방법으로의 가능성을 제시하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제16권1호
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• pp.65-70
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• 2012

Synaptic long-term potentiation (LTP) and long-term depression (LTD) have been studied as mechanisms of ocular dominance plasticity in the rat visual cortex. Serotonin (5-hydroxytryptamine, 5-HT) inhibits the induction of LTP and LTD during the critical period of the rat visual cortex (postnatal 3~5 weeks). However, in adult rats, the increase in 5-HT level in the brain by the administration of the selective serotonin reuptake inhibitor (SSRI) fluoxetine reinstates ocular dominance plasticity and LTP in the visual cortex. Here, we investigated the effect of 5-HT on the induction of LTP in the visual cortex obtained from 3- to 10-week-old rats. Field potentials in layer 2/3, evoked by the stimulation of underlying layer 4, was potentiated by theta-burst stimulation (TBS) in 3- and 5-weekold rats, then declined to the baseline level with aging to 10 weeks. Whereas 5-HT inhibited the induction of LTP in 5-week-old rats, it reinstated the induction of N-methyl-D-aspartate receptor (NMDA)-dependent LTP in 8- and 10-week-old rats. Moreover, the selective SSRI citalopram reinstated LTP. The potentiating effect of 5-HT at 8 weeks of age was mediated by the activation of 5-$HT_2$ receptors, but not by the activation of either 5-$HT_{1A}$ or 5-$HT_3$ receptors. These results suggested that the effect of 5-HT on the induction of LTP switches from inhibitory in young rats to facilitatory in adult rats.

• 교육시설 논문지
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• 제27권3호
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• pp.3-14
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• 2020

The purpose of this study is to discuss the planning direction of educational spaces to support children's healthy and creative learning based on bio_philic theory. This study analyzed the characteristics of the application of biophilic patterns in children's education space through case analysis. The conclusion of this study is summarized as follows. As a result of the analysis of children's classroom space, the pattern of 'A(Visual connection with nature), F(Dynamic & Diffuse Light), K(Prospect)' shows high application rate, but the pattern of 'C(Non-Rhythmic Sensory Stimuli), G(Connection with Natural Systems), I(Material Connection with Nature)' shows low application rate. In particular, there is a lack of connection with patterns such as hearing, smell, touch, taste stimulation and water experience, and curiosity through exploration of nature about 'B(Non-visual connection with nature), E(Presence of Water), N(Risk/Peril)' changes in nature and ecosystem. In the corridor and rest space, the pattern of 'A(Visual connection with nature), D(Thermal & Airflow Variability), F(Dynamic & Diffuse Light), G(Connection with Natural Systems), K(Prospect)' shows high application rate, but 'B(Non-visual connection with nature)' shows low application rate. In addition, the application of patterns related to the stimulation of curiosity through direct exploration of nature and the exploration of the patterns of 'E(Presence of Water), N(Risk/Peril)' is insufficient. Therefore, in the case of classroom spaces, the active use of nature as it is should be considered within the scope that does not cause visual confusion, and it should provide an area that can be experienced through the five senses. And corridors and rest spaces should be designed to introduce more active natural elements as spaces to recover stress caused by learning. In other words, the characteristics of children's education facilities need to be connected between classroom space, corridor, rest space and external space. This study is meaningful in that it analyzes and derives the application characteristics of 'biophilic design' which affects the 'Attention Restoration' of children's educational spaces through foreign cases.

• Journal of Korean Neurosurgical Society
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• 제46권3호
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• pp.273-276
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• 2009

A 54-year-old man experienced injury to the second finger of his left hand due to damage from a paintball gun shot 8 years prior, and the metacarpo-phalangeal joint was amputated. He gradually developed mechanical allodynia and burning pain, and there were trophic changes of the thenar muscle and he reported coldness on his left hand and forearm. A neuroma was found on the left second common digital nerve and was removed, but his symptoms continued despite various conservative treatments including a morphine infusion pump on his left arm. We therefore attempted median nerve stimulation to treat the chronic pain. The procedure was performed in two stages. The first procedure involved exposure of the median nerve on the mid-humerus level and placing of the electrode. The trial stimulation lasted for 7 days and the patient's symptoms improved. The second procedure involved implantation of a pulse generator on the left subclavian area. The mechanical allodynia and pain relief score, based on the visual analogue scale, decreased from 9 before surgery to 4 after surgery. The patient's activity improved markedly, but trophic changes and vasomotor symptom recovered only moderately. In conclusion, median nerve stimulation can improve chronic pain from complex regional pain syndrome type II.

• 전기의세계
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• 제21권5호
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• pp.7-12
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• 1972

Applying the theory of physiology and control systems, the visual system was studied as a regulator of impining light. The characteristics function of visual system is mainly analysed by spato-temporal characteristics based upon Enroth's model, Broca-Sulzer phenomenon and Mach effect. Some aims of this paper are as follows. (1) In order to get the excitatory and inhibitory potential of the intermediated cell layer in the retina, the exponential value, {exp(FM/kT)- $I_{mn}$ } is caculated based on the physiological theory in neuro-phenomena. (2) To show the visual characteristics by analog simulation for generating stimulus waveforms and analysis, the visual adaptation was recorded as electrical stimulation in the form of step functions. Furthermore, ti is shown that the above experimental data agrees satisfactorily with the theoretical (psychophysiological) values. This study is expected to lead to further studies concerned with human observer and human operator in control and especially pattern recognition systems.stems.

• 대한의용생체공학회:의공학회지
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• 제31권5호
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• pp.359-364
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• 2010

The purpose of the brain-computer (machine) interface (BCI or BMI) is to provide a method for people with damaged sensory and motor functions to use their brain to control artificial devices and restore lost ability via the devices. Functional electrical stimulation (FES) is a method of applying low level electrical currents to the body to restore or to improve motor function. The purpose of this study was to develop a SSVEP-based BCI rehabilitation training system with FES for spinal cord injured individuals. Six electrodes were attached on the subjects' scalp ($PO_Z$, $PO_3$, $PO_4$, $O_z$, $O_1$ and $O_2$) according to the extended international 10-20 system, and reference electrodes placed at A1 and A2. EEG signals were recorded at the sampling rate of 256Hz with 10-bit resolution using a BIOPAC system. Fast Fourier transform(FFT) based spectrum estimation method was applied to control the rehabilitation system. FES control signals were digitized and transferred from PC to the microcontroller using Bluetooth communication. This study showed that a rehabilitation training system based on BCI technique could make successfully muscle movements, inducing electrical stimulation of forearm muscles in healthy volunteers.